This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this grant is and to test the safety and efficacy of a novel organophosphorus pesticide degrading enzyme, OpdA, in an NHP model. Proof that the enzyme is safe and effective against parathion and dichlorvos should provide the necessary impetus for further development for human use. Our central hypothesis is that OpdA is safe and improves survival after poisoning with parathion and dichlorvos.